Fireproof fabric and process of making same



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' [we W earch Room Jan. 1925- 1,523,813 w. G. LINDSAY FIREPROOF FABRIC AND PROCESS OF MAKING SAME Filed Dec. 14, 1917 15232513 UR m ma/2M y Patented llan. 20, 1925.

- UNITED STATES PAT/ENT OFFICE.

WILLIAM G. LINDSAY, OF NEWARK, NEW JERSEY, ASSIGNOR TO THE OELLULOD) COMPANY, A CORPORATION OF NEW JERSEY.

Application filed December 14, 1917. Serial No. 207,116.

7 all whom it may concern:

Be it known that I, WILLIAM G. LINDSAY,

a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Fireproof Fabrics and Processes of Makin Same, of which the following is a speci cation.

The principal object of my invention is to provide a new and improved coated fire proof fabric for use in various places, and amethod of preparing the same; This and other objects will be indicated in connection with the following specification, in which I have disclosed onespecific embodiment of my invention and the procedure in accord-.

ance therewith.

My improved coated fireproof fabric is especially adapted for use on airplane wings. ,After the wing frames have been made, the cloth is ordinarily wrapped once around the frame, sleeve-like, and then coated with some varnish-like preparation. It is highly desirable that the fabric be fireproof, but it is difficult to obtain this quality and at the same time get other desirable characteristics, such as waterproofing, strength, flexibility, and a proper shrinkage of the fabric so as' to draw it on the frame.

Many attempts have been made to make a non-inflammable coating to be applied to fabrics so that the resulting coated fabric may be fireproof. Many coating substances that have excellent qualities in other respects have not been found available for a fireproof product because they have some degree of inflammability, or because they are not fireproof in themselves to counteract the normal inflammability of the unt treated fabric. Such coating substances as pyroxylin or acetyl cellulose have desirable ualities of water-proofness, shrinking efect, etc., but whenapplied to a fabric they do not give an effectively fireproof product. By my invention herein disclosed, I have made it possible to employ such substances as those mentioned above, and yet secure fire fireproofing substance and then coating it with a coating of reduced or low inflammability, whereby the resultant coated fabric will be effectively fireproof.

The product is shown in the accompanyingdrawings, in which Figs. 1 and 2 are sections, thelatter enlarged, of a fabric coated with the resultant composition.

i yinvention may be practiced in a variety of ways; I will now give one specific example of procedure in accordance therewith. The fabric is first applied to the-airplane frame and sewed in place, being drawn to such anordinary degree of tightness as may be. convenient for sewing. Of course, it should bemade much tighter than this when ready for service. Next, a water solution of ammonium phosphate is applied with a brush thoroughly saturating the cloth. Then the treated cloth is allowed to dry, leaving it impregnated with the ammonium phosphate.

I prepare a solution of nitrocellulose and tricresylphosphate according to the following formula:

. Parts. Pyroxylin 100 Tricresylphosphate 50 Acetone 300 Methyl alcohol 600 Amyl acetate 300 For the nitrocellulose I use a good soluble variety such as is ordinarily well known to manufacturers of celluloid. This pyroxylin solution is then applied with a brush and, after it dries, another coat may be applied if so desired and so on to any number of" .of friction' with the air.

In the drawings, the fabric is indicated at A, and the coating composition at B, C. The dried ammonium phosphate will be in the form of crystals which will adhere to the fibres of the fabric and arrange themselves in irregular ma'ner. The pyroxylin solution will penetrate into the crevices bein a;

tween the ammonium phosphate crystals and obviously in many places to the fabric itself. At the same time the crystals will be more or less surrounded by and mixed with the pyroxylin thereby forming a more or less intimate mixture between the pyroxylin and the ammonium phosphate, which mixture intimately unites with the fabric to form a unitary structure. If the coating be physically separated from the fabric it will carry with it more or less of the ammonium phosphate. The essential functioning of the substances is that they cooperate to provide a fireproofer for the fabric and a waterproof'er for the fireproofer and the fabric, the composition also acting to shrink the fabric.

The fabric prepared in this way is effectively fireproof, also waterproof. By waterproof I mean not merely that quality which prevents the passage of water "through the flexible material but that quality by virtue of which the surface of the material remains intact despite itscontinued contact with water, this latter quality resulting from the above described treatment. I believethat this action is due to the fact that the crystals are submerged below the surface and are'protected by the cellulosic composition. The tricresylphosphate materially reduces the inflammability of the pyroxylin so that the coating alone, that is apart from. the fabric, would have a low degree of inflammability. It may be called a coating of low or reduced inflammability. By applying this coating to the fireproofed fabric, such as that treated with the ammonium phosphate, the resultant prepared fabric if thoroughly fireproof.

.By suitably varying the process and the. ingredients, a variety of so called artificial leather may be prepared which, unlike many artificial leathers, will be non-inflammable.

Various other applications of the process Will suggest themselves, such as for fireproofing sails and fabrics in various situations.

The first treatment of the fabric with the ammonium phosphate is for the. purpose of firproofin'g it and any other suitable fireproofing agent may be employed, such, for

example, as ammonium sulphate, or ammonium chloride, or boric acid, or stannic creasing the amount of tricresylphosphateis to decrease the shrinkage of the fabric and to increase the flexibility of the coating. Various suitable solvents may be employed,

'wise other well known similar substances,

known as dope, containing a volatile solvent which evaporates and leaves a tough flexible waterproof coating, may be employed, with or without a separate inflammability decreaser, according to the nature of the substance.

I claim:

1. The process of making a flexible fireproof coated fabric. which consists in first impregnating the fabric with a solution of a fireproofing substance adapted to give off a fire smothering gas in sufiicient quantity to act effectively as a fire retarder, drying "the water from said solution, and then coating the impregnated fabric with combustible material containinga fire retarding ingredient, the said coating substance not being asolvent of the said fireproofing substance.

2. Thei process of making a fireproof coatedfabric, which consists in first impregna ting the fabric with a water solution of afireproofing substance adapted to give off water of combination in sufficient quantity to act effectively as a fire retarder,

drying the vvater from said solution, and

then coating the impregnated fabric with a combustible composition containing an inflammability reducing substance of essentially different composition from said fireproofing substance.

3. The process of producing a flexible fireproof sheet material which consists in starting with a basic sheet material, making an evenly distributed application of a solution of ammonium phosphate thereto, drying the solvent out of said solution and then coating it with a flexible waterproofing substance having intimately associated therewith an ingredient to render it of low inflammability, said ingredient being cssentially different from said fireproofing substance and said coating composition being dissolved in a volatile solvent which is not a solvent of the ammonium, phosphate, then evaporating the solvent so as to leave a flexible adherent coat of said composition on the sheet material.

A. A product comprising a fabric coated with a composition containing afire proof CROSS ing substance adapted to give off water of combination in sufficient quantity to act effectively as a fire retarder and a water proofing substance comprising a cellulose ester. I

5. A flexible fireproofed coated fabric on a frame consisting of a fabric impregnateil withla dried solution of ammonium phosphate and coated with a coating containing a cellulose ester and a fire retarding constituent, the fabric being stretched tightly on the frame by the shrinkage of said coatll. The process of making a flexible fireproof coated fabric which consists in first impregnating the fabric with a solution of fireproofing substance adapted to give off water of combination in suflicient quantity to act effectively as a fire retarder, and

then evaporating the solvent from said fire-- proofing substance, and then coating it with a flexible coat of low inflammability coniprising a cellulose ester, an inflammability reducing substance for said cellulose ester and a solvent, and then evaporating said last named solvent.

7. The process of making a non-inflammable fireproof coated fabric which consists in first impregnating the fabric with a fireproofing substance dissolved in a solvent which is'not a solvent of acetylcellulose, evaporating said solvent, and then coating it with a composition containing acetylcellulose and an inflammability reducing substance for said acetylcellulose and a solvent whichis not a solvent of said fireproofing substance, and then evaporating said last-named solvent.

S. The process of making a fireproof coated fabric which consists in first impregnating the fabric with a solution of fireproofing salt adapted to give off water of combination in sufficient quantity to act effectively as a fire retarder, drying out the solvent leaving the salt with its water of combination in the fabric, and then applying one or more coats of acetyl cellulose and an inflammability reducer for said acetyl cellulose of essentially different composition fromsaid salt.

9. The process of making a. fireproof coated fabric which consists in first impregnating the fabric with ammonium phosphate, and then coating it with a composition containing acetyl cellulose, and an inflammability reducing ingredient for said acetyl cellulose essentially different from said ammonium phosphate.

10. The process of making a flexible fireproof coated fabric, which consists in first applying to the fabric a fire retarding constituent adapted to absorb heat due to the chemical change therein when heated, and then applying a combustible waterproof coating containing an infiammability re- REFERENCE Search Recs ducing substance, the said constituents bcmixture of cellulose ester and tricresylphosphate, the ammonium phosphate being presas a fire retarder.

12. The process of making a waterproof and fireproof coated fabric, which consists in first impregnating the fabric with a soluent in sufficient quantity to act effectively tion of a fireproofing substance, adapted to 4 give off water of combination insufficient quantity to act effectively as a fire retarder, drying the solvent from said substance, stretching the fabric upon a frame, and then coating it with a waterproof coat containing a cellulose ester composition of low inflammabilit-y, and drawing said fabric tightly upon'a frame by shrinkage of said coating. e

13.- The process of making a fireproof coated fabric shrunken on ..a frame, which consists'in impregnating the fabric with an aqueous solution of fireproofing substance adapted to give ofi a fire smothering gas containing water in sufficient quantity to act effectively as a. fire retarder, and applying it to the frame, evaporating the water from said substance excepting the water of combination, and then coating the fabric With a waterproof coat containing a cellulose ester composition of low infiammability and shrinking it upon the frame by the drying of said coat.

14. A product comprising a cellulose ester and an aromatic phosphate and in close association therewith a fire retarding constituent adapted to give ofi a fire smothering gas in suificient quantity to act effectively as a fire retarder.

15. A product containing a cellulose ester and an aromatic phosphate and in close association therewith ammonium phosphate in sufficient quantity to act effectively as a fire retarder.

16. A body having on its surface a waterproof material containing a cellulose ester and in close association therewith ammonium phosphate in sufficient quantity to act effectively as a fire retarder.

17. A body having on its surface a material containing a waterproof combustible constituent and in association therewith a soluble fire retarding constituent adapted to give off a fire smothering gas containing water in sufficient quantity to act effectively as a fire retarder.

18. A product containing in close association a cellulose acetate, tricresylphosphate and ammonium phosphate, the two last named substances being present in sufiicient quantity to act effectively as a fire retarder.

19. A product comprising in close asso- 5 ciation a compound of ammonia, a compound of cellulose and an aromatic phosphoric ester.

20. An article having a surface of tough, plastic material, composed of cellulose acetate plasticized by an aromatic phosphate, said material containing as a fire retarding agent, ammonium phosphate.

WILLIAM G. LINDSAY. 

